Jose Mourinho could barely raise a smile but you can bet Jurgen Klopp did - a smile as wide as the Mersey.

If Klopp needed a beer after that painful derby at Goodison Park, this was the perfect excuse to crack one or two open.

Never mind Manchester City having to wait to formalise the Premier League title - that is pretty much a footnote to the immediate implications of this remarkable defeat.

Lifting and inspiring his team ahead of Tuesday’s return Champions League leg against Klopp’s Liverpool will be one of the toughest challenges faced by Guardiola in his bejewelled coaching career.

Physically, they looked spent, not just the effect of a gruelling, occasionally spiteful, derby game but perhaps the culmination of their relentless efforts over the entire piece this season.

(Image: Offside)

And where they are psychologically is anyone’s guess.

Can, for example, Raheem Sterling recover from this in the short term?

He will be reflecting on his misses in this game - chances to bury United long before the astonishing second half comeback - for a long time.

He will watch re-runs of Pep’s head-in-hands anguish when those opportunities were lifted into the stands and agonise. Guardiola knew how costly they could be.

How can Vincent Kompany and Nicolas Otamendi face Liverpool with any degree of confidence when their fallibility was again exposed?

The fact that John Stones cannot even get into the squad, incidentally, is a worry for Gareth Southgate and the player himself.

For all their expenditure, City’s central defensive area is still soft by elite class standards.

Both Paul Pogba’s goals and Chris Smalling’s winner were testament to that.

Kevin de Bruyne couldn't save the day from the bench (Image: Manchester City FC)

When the dust settles on this fractious occasion and on the season itself, that is one area Guardiola must address … again.

It is not the only one.

Additions in the attacking category are inevitable. With Sergio Aguero and Gabriel Jesus on the bench, there was no-one to take up a central role, although Bernardo Silva, all five foot-nothing of him, gave it the occasional crack.

As defensively vulnerable as they were here and at Anfield, City - with Jesus struggling - badly missed a useful attacking focal point.

That will be addressed by Sheikh Mansour’s wealth.

Obviously, the Sheikh was not in attendance, even though it would have given him the chance to rub shoulders with Gianni Infantino, in the extremely unlikely event he has a clue who the president of FIFA is.

Infantino must have been wowed by the frenetic occasion, if not the officiating.

There will be no English referees at the World Cup and no wonder, if Martin Atkinson’s performance is a barometer of the overall standard.

He was shocking, although Ashley Young would disagree, having been allowed to handle in the area and top Aguero with a full set of studs, also in the penalty box.